The following relates to providing load flexibility to a power supply device. It finds particular application with monitoring current and/or power consumption and regulating output of a power supply device.
Power supplies provide power to various electronic components employed in various machines, control processes, etc. Increased and unique power demands may require the development of a revised power supply. In one example, power supplies utilize several different voltages to power various components associated with a personal computer (PC). The power supply can provide each of these voltages, in varying amounts of power depending on the model, directly from its circuitry.
The amount of load required by a particular power supply is often specified as its maximum load. These maximum current requirements can be listed as part of the power supply's output specifications. The amount of load required can vary considerably between different form factors, between manufacturers and between specific designs from the same manufacturer.
In general, when a power supply's output is discussed, a particular number of watts are specified. An output rating refers to the nominal, total maximum output power of all the voltages that the power supply provides. With relation to DC electricity, the computation of power is determined by multiplying its current in Amps, and its voltage in Volts. Typically, however, power supplies produce several different voltages rendering such a basic computation insufficient.
Output specifications for a power supply, generally include all the different voltages that the power supply provides, and the amount of current it can supply for each. This is sometimes called the power distribution for the supply. Each voltage produced by a power supply can be employed for a different purpose, which is why individual current ratings should be checked for each voltage, and not just use the total wattage of the supply. The goal behind analyzing the power supply's output rating and power distribution is to match it to the needs of your system to ensure it will provide the power needed. The key problem is to determine exactly how much power a given system uses.
For instance, with regard to peripheral components, the current (or power) rating of a device such as a hard disk, refers to the manufacturer's claim of how much the device uses during normal, continuous operation. The actual peak draw of the device is at its maximum, however, at startup—not while it is running. The +12 voltage provided by the power supply is used primarily to drive disk drive motors. Because of their design, these motors can take up to double their steady-state current when they are spinning up from rest. For example, if three or four hard disks are employed in a system and all of them start up at the same time, this can be a tremendous demand on your power supply's ability to provide +12V power.
At any given point in time, each voltage line may have dynamic power requirements. Conventionally, in order to accommodate such fluid power requirements, a power supply would have to be designed to accommodate power that far exceeded normal usage levels. Such increased and unique power demands can cause frequent power supply redesigns resulting in excess development and implementation costs as well as delayed implementation schedules. Such power demands are difficult to predict in the near term. Thus, systems and methods are needed to flexibly determine and provide appropriate current and power required by particular components within a system.